A relatively low cost offshore terminal, particularly for production of hydrocarbons from subsea wells, can be formed by the use of a dedicated storage vessel which floats at the sea surface and supports a transfer structure beyond an end of the vessel. The transfer structure is loosely anchored, as by several catenary chains that extend down to the sea floor, and is coupled by a flexible underwater conduit to a pipeline at the sea floor which may be connected to undersea wells. While such an installation can often substitute for a massive offshore production platform, the floating vessel may not be as sturdy as a massive platform in resisting extreme surface conditions such as ice flows and hurricanes. If the floating vessel with transfer structure could be made to avoid damage under extreme adverse conditions such as ice flows and hurricanes, then it would become even more valuable.